I do disagree with this, in that #Bing's search results aren't just bad because they can only crawl 90% of the sites that #Google can. Bing's results are bad because their ranking algorithms fail to put the information people are searching for at the top of the results. If one clicks through 9 or 10 pages of results, one might find something relevant, which was probably why #Yahoo and #DDG used to deliver better results than Bing, while sourcing most or all of their results from Bing.
AFAIK, #Brave search uses its own crawler and index, as does #Gigablast. And let us not forget #YaCy. I intend to host a YaCy peer-to-peer search instance on its own VPS (well, shared with a #Searx instance, which will use it)
DDG used to be better than Google at most searches, but in recent years, their results (and Yahoo's also) are almost identical in content and ordering to Bing's results. And Bing is clearly inferior, except with content that is hosted on Microsoft's own sites.